The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In general, a complete car company determines a target engine revolution per minute (RPM) during idling through a plurality of vehicle tests, and an engine controlling apparatus performs an operation for maintaining a target engine RPM via an idle controller, ignition, and fuel control.
That is, vibration is generated and controlled during driving of an engine in such a manner that a controller controls a fuel injection rate such that the generated vibration converges on a target RPM that is pre-input to the controller. We have discovered, however, that in certain cases, when a drive system resonance frequency and an idle fuel amount control period are coupled, vibration becomes serious rather than being removed.
In particular, such vibration becomes more serious at a cold time and accordingly, this gives displeasure to users due to noise, vibration, and so on to make consumer dissatisfaction.